1. Field of the Invention
The present invention relates to a magnetic head for recording a magnetic signal in a recording medium and reproducing the same therefrom, and more particularly, to a magnetic head having an improved upper pole for recording a magnetic signal.
2. Description of the Related Art
Apparatuses for recording and reproducing a magnetic signal in and from a predetermined recording medium, such as, hard disk drives, have a magnetic head for performing recording and reproduction. As shown in FIG. 1, a magnetic head 10 is installed in a slider 20 installed on one end of a swing arm 30, and moves to a desired track position over a recording medium (not shown) by pivoting of the swing arm 30 to perform recording or reproduction.
FIG. 2 is a magnified perspective view of the magnetic head 10. As shown In FIG. 2, the magnetic head 10 includes a magneto resistive head 14 for reproduction and an induction recording head for recording. The magneto resistive head 14 detects and reads a magnetic signal from a recording medium. The induction recording head includes an upper pole 11 and a lower pole 12 for forming a leakage magnetic flux and a recording coil 13, which is a current supply route, to record a magnetic signal of a desired content in a recording medium.
In particular, the induction recording head determines the quality of a signal input to a recording medium. Accordingly, if the input via the induction recording head is not clean, the magneto resistive head 14 cannot perform satisfactory reproduction even if it has an excellent performance.
In recent trends, recording mediums reduce the width of tracks to which a magnetic signal is input, in order to increase their storage capacity. When the width of tracks is reduced, the width w of the upper pole 11 of the induction recording head which receives a magnetic signal must also be reduced in conformity to the reduced width of tracks. However, the reduction of the width w of the upper pole 11 increases the edge effect of a magnetic field generated by the induction recording head, so that the vertical component of the magnetic field is measured as having a pattern in which it is concentrated at the edges of the upper pole, as shown in FIG. 3. When a magnetic signal is recorded on the recording medium in this state, the shape of magnetized areas on the recording medium representing recorded data is apt to a horse shoe as shown in FIG. 4. This horse shoe shape denotes unclear and unclean recording of a magnetic signal on a track. Thus, clean input of a magnetic signal is achieved by improving the seagull shape of magnetization to a rectangular shape. Therefore, a magnetic head capable of maintaining the magnetization shape rectangular even when the track width is reduced is required.
To solve the above problem, an objective of the present invention is to provide an improved magnetic head by which the shape of magnetized areas on a recording medium representing recorded data is maintained rectangular even when the width of the tracks of the recording medium is reduced.
To achieve the above objective, the present invention provides a magnetic head including an upper pole and a lower pole for generating a leakage magnetic flux to magnetize a recording medium to have a predetermined pattern, wherein the upper pole has a [structure] pentagonal cross-section in which the central portion of a side opposite to the recording medium is thicker than the edges of the side.
To achieve the above objective, the present invention provides a magnetic head having an upper pole and a lower pole for generating a magnetic flux to magnetize a recording medium to have a predetermined pattern. The upper pole has a bottom surface designed to be adjacent to a recording medium, two side surfaces and a top surface. The top surface extends between edges of the side surfaces without extending over the side surfaces, wherein a thickness of the upper pole measured from the top surface to the bottom surface is greater at a central location than at the edges of the side surfaces.